The present invention refers to a sealing ring for use in an antifriction bearing, and more particularly to a magnetic liquid sealing ring.
In a known seal of this type which is used, for instance, in a ball bearing, a magnetic liquid sealing ring is arranged on the bearing outer ring. That sealing ring faces a cylindrical surface of the inner ring, with a small slot radially between them. A magnetic liquid is held fast in that slot by a magnet. In order to prevent mixing of the magnetic liquid with the lubricant of the antifriction bearing as far as possible, a pre-seal element is fastened to the magnetic liquid sealing ring on the axial side toward the balls. The pre-seal comprises a metal disc with a sealing edge which, with a slight slot radially between them, faces the cylindrical surface of the inner ring. If the sealing edge were to rest against the bearing inner ring, that would produce too large a moment of friction for many installations However, this slot at the pre-seal is highly likely to permit bearing lubricant to enter the magnetic liquid and mix with it over time, which would destroy the sealing action at the magnetic liquid.